jdbc例子

jdbc:Java 数据库连接，（Java Database Connectivity，简称JDBC）是Java语言中用来规范客户端程序如何来访问数据库的应用程序接口

以下以数据库mysql为例

在https://www.cnblogs.com/luoa/articles/9686483.html的这个项目里创建class JdbcTest

package com.aluo.spring;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class JdbcTest {
    private static Connection getConn() {
        String driver = "com.mysql.jdbc.Driver";
        String url = "jdbc:mysql://localhost:3306/luo";
        String username = "root";
        String password = "123456";
        Connection conn = null;
        try {
//            Class.forName(driver); // classLoader,加载对应驱动
            conn = (Connection) DriverManager.getConnection(url, username, password);
            System.out.println(conn);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }

    private static int insert(Student student) {
        Connection conn = getConn();
        int i = 0;
        String sql = "insert into user (id,phone,password) values(?,?,?)";
        PreparedStatement pstmt;
        try {
            pstmt = (PreparedStatement) conn.prepareStatement(sql);
            pstmt.setInt(1, student.getId());
            pstmt.setString(2, student.getPhone());
            pstmt.setString(3, student.getPassword());
            i = pstmt.executeUpdate();
            pstmt.close();
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return i;
    }

    private static int update(Student student) {
        Connection conn = getConn();
        int i = 0;
        String sql = "update user set phone='" + student.getPhone() + "' where id='" + student.getId() + "'";
        PreparedStatement pstmt;
        try {
            pstmt = (PreparedStatement) conn.prepareStatement(sql);
            i = pstmt.executeUpdate();
            System.out.println("resutl: " + i);
            pstmt.close();
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return i;
    }

    private static Integer getAll() {
        Connection conn = getConn();
        String sql = "select * from user";
        PreparedStatement pstmt;
        try {
            pstmt = (PreparedStatement) conn.prepareStatement(sql);
            ResultSet rs = pstmt.executeQuery();
            int col = rs.getMetaData().getColumnCount();
            System.out.println("============================");
            while (rs.next()) {
                for (int i = 1; i <= col; i++) {
                    System.out.print(rs.getString(i) + "\t");
                    if ((i == 2) && (rs.getString(i).length() < 8)) {
                        System.out.print("\t");
                    }
                }
                System.out.println("");
            }
            System.out.println("============================");
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }

    private static int delete(Integer id) {
        Connection conn = getConn();
        int i = 0;
        String sql = "delete from user where id='" + id + "'";
        PreparedStatement pstmt;
        try {
            pstmt = (PreparedStatement) conn.prepareStatement(sql);
            i = pstmt.executeUpdate();
            System.out.println("resutl: " + i);
            pstmt.close();
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return i;
    }
    public static void main(String[] args) {
        getConn();
        // System.out.println(insert(new Student(4,"123456789100","0000")));
        // System.out.println(update(new Student(4,"1111111111","0000")));
        getAll();
//        System.out.println(delete(4));
    }

}

package com.aluo.spring;

public class Student {
    private Integer id;
    private String phone;
    private String password;
    private String name;
    private String ide;
    private String tradePassword;
    
    public Student(Integer id, String phone, String password) {
        super();
        this.id = id;
        this.phone = phone;
        this.password = password;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getIde() {
        return ide;
    }

    public void setIde(String ide) {
        this.ide = ide;
    }

    public String getTradePassword() {
        return tradePassword;
    }

    public void setTradePassword(String tradePassword) {
        this.tradePassword = tradePassword;
    }

}

参考：http://www.cnblogs.com/wuyuegb2312/p/3872607.html